Overview
Leiodidae are abundant in decaying organic matter and also occur in carrion, fungus fruiting bodies, some types of dung and nests of vertebrates; they are abundant in caves in most parts of the world but have not yet been recorded from Australian caves. Many are general scavengers, but certain groups are associated with particular fungi (
Neopelatops
with slime moulds; some
Nargomorphus
with puffballs; some leiodines and probably
Colon
with hypogean fungi) (Newton 1984). Species of
Myrmecholeva
are very unusual in that both larvae and adults have sucking mouth-parts consisting of a labro-labial tube and styliferous mandibles and maxillae; they have been recorded from ant nests (Lea 1910) but appear to be more generally distributed and may be mycophagous, rather than predacious.
Description
Moderately small beetles with more or less spiny legs and simple tarsi (fore and occasionally mid tarsi modified in some males and in
Colon
) differing from most other staphylinoids in having the abdomen entirely concealed by the elytra. Almost all species with 5-segmented antennal club, having 2nd segment (8) smaller (shorter or shorter and narrower) than either 1st (7) or 3rd (9); club sometimes very weak (
Eublackburniella
,
Nargiotes
) with segment 8 only slightly reduced, or very strong (
Dietta
,
Zeadolopus
) with 8 greatly reduced or absent.
Colon
differ in having a 4-segmented club with segment 8 larger than 7. Leiodids also possess a unique type of internal sensory vesicle usually opening on the distal surfaces of segments 7, 9 and 10 (Corbi
e
re-Tichane 1974; Peck 1977). Larvae, like those of most staphylinoids, are of the active, campodeiform type with urogomphi which are almost always articulated at the base; they differ from staphylinid larvae in usually having mandibular mola and 2 apical maxillary lobes (galea and lacinia).
Distribution
Leiodinae are usually glabrous and strongly convex and may have burrowing adaptations, such as enlarged legs (
Dietta
,
Zeadolopus
); most other leiodids are pubescent. Camiarinae, including
Eublackburniella
,
Myrmecholeva
and the Agyrtodini, are restricted to the Southern Hemisphere, while the Cholevinae occur throughout the world and are represented in Australia by
Austronemadus
,
Catoposchema
,
Nargiotes
and several other genera. Coloninae (
Colon
) also occur in Australia, but Catopocerinae and Leptininae are absent from the fauna. [Newton 1985; Zwick 1979.]